The present invention relates generally to a motor vehicle child seat and in particular to an energy absorbing child seat:.
Special child seats that provide protection for small children in motor vehicles are well known. Two different types of child seats have been developed. One type is a separate seat which is placed upon a vehicle seat and attached thereto by the seat belt provided as part of the vehicle seat. A second type of child seat, commonly referred to as an "integral child seat," has the components of the child seat built into the vehicle seat. Integral child seats typically include one or more moveable components which, in one position, enable use of the vehicle seat by an adult, and in a second position enable use by a small child. Common elements of both types of child seats are a lower seat support, a back support panel and a restraint system for the seat occupant. The restraint system generally includes one or two shoulder belts which are operatively connected between the back support panel and the seat support to restrain a passenger positioned on the seat support and against the back panel.
Any vehicle passenger, a child or an adult, can sustain neck injuries when restrained in a seat by a shoulder belt. When the vehicle is involved in a front impact vehicle collision, the passenger's torso is restrained against the seat back by the shoulder belt while the passenger's head is free to move forward, bending the neck and possibly over extending the neck muscles. In small children, the ratio of the head mass to the body mass is higher than for an adult. As a result, children are somewhat more likely to receive neck injuries in a given vehicle collision. The present invention seeks to reduce neck injuries in children by providing energy absorbing mounting brackets to connect the back support panel of the child seat to the supporting seat structure or frame. The energy absorbing brackets allow the back support panel to move forward relative to the seat frame. For a child seat in the rear seat of a vehicle, ample space is available for the back support panel movement. The result is reduced relative velocity and deceleration between the child's head and shoulders, thereby reducing neck loads and injuries.
The present invention employs brackets which are plastically deformable under a predetermined load and are designed for specific load versus deflection characteristics which will provide the desired energy absorption. During normal seat loading in the absence of a vehicle collision, the seat brackets will hold the back support panel substantially rigidly to the seat structure. The energy absorbing brackets are designed to plastically deform only during the relatively high loading experienced in a vehicle collision.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.